The present disclosure relates to the field of power supplies, and more particularly to methods and systems for improving regulation efficiency of a direct current-to-direct current (DC-DC) converter included in an information handling system.
As the value and use of information continues to increase, individuals and businesses seek additional ways to acquire, process and store information. One option available to users is information handling systems. An information handling system (‘IHS’) generally processes, compiles, stores, and/or communicates information or data for business, personal, or other purposes thereby allowing users to take advantage of the value of the information. Because technology and information handling needs and requirements vary between different users or applications, information handling systems may also vary regarding what information is handled, how the information is handled, how much information is processed, stored, or communicated, and how quickly and efficiently the information may be processed, stored, or communicated. The variations in information handling systems allow for information handling systems to be general or configured for a specific user or specific use such as financial transaction processing, airline reservations, enterprise data storage, entertainment, and/or global communications. In addition, information handling systems may include a variety of hardware and software components that may be configured to process, store, and communicate information and may include one or more computer systems, data storage systems, and networking systems.
Presently, many DC-DC converters provide over current protection (OCP) by sensing the voltage across the synchronous rectifier (low side switch) and comparing the voltage to a maximum value. Since the voltage is proportional to the current flowing through the switch, a need for a separate current sense resistor is often eliminated.
However, the proportionality factor that defines the relationship between the voltage and the current is dependent on the switch parameters such as on resistance. Typically, a value of the on resistance has a large degree of variance with respect to a nominal or rated value since it is dependent on semiconductor material properties, which may vary with each production run. That is, the value of on resistance may vary significantly, e.g., 100% variation, compared to the rated value, thereby causing a large variation in the current. For example, if an OCP set point is defined to be 110% of the rated current value, the actual value of current at which the OCP is triggered may vary from 110% of rated current and 220% of the rated current. Adoption of best design practices may result in the selection of an inductor capable of carrying 220% of the rated current, often resulting in increased cost and space. Failure to select a properly rated inductor may cause an undetected over current condition, thereby increasing inductor saturation, resulting in over voltage and causing possible damage to a load connected to the DC-DC converter.
Therefore, a need exists for regulating a DC-DC converter of a power supply. More specifically, a need exists to provide a DC-DC converter having an improved current sensing technique that provides a narrower range of variance in OCP set points. Accordingly, it would be desirable to provide for a more efficient and reliable power supply included in an IHS, absent the disadvantages found in the prior methods discussed above.